At my office, there’s a chess board set up in the corner of the room near the watercooler in the meeting room. When I started working here, the pieces were mostly in their starting position except a couple moves had been made. This never changed so I figured nobody ever used it. I decided to play an extended game with myself, so every time I went into that room to get water, I made a move. First for white, then for black, etc. After a few moves, I came back and noticed somebody else had taken a turn for white. So I responded for black. This has been going back and forth for a while now. I’m playing a very long game of chess with somebody at this office and I have no idea who it is. Currently we are even in material and my opponent has a slightly better position.
Update: We found out who we have been playing against.